posterior intercostal veins

Definition: veins draining the intercostal spaces posteriorly; those of the first 1-C space drain into the brachiocephalic veins; from spaces 2–3, they drain into right and left superior intercostal veins; from the 4th–11th spaces on the right, they are tributaries of the azygos vein; on the left, they empty into either the hemiazygos or accessory hemiazygos veins.